Preparation of sulfenamides by catalytic oxidation

ABSTRACT

Metal phthalocyanines are oxidation catalysts for the preparation of sulfenamides in the reaction of primary or secondary amines with 2-mercaptobenzothiazole, an alkali metal salt of 2-mercaptobenzothiazole, a dithiocarbamate, a dithiocarbamic acid, a thiuram disulfide, or 2,2&#39;&#39;dithiobis(benzothiazole).

United States Patent [.191

Campbell et al.

[ 51 June 5, 1973 PREPARATION OF SULFENAMIDES BY CATALYTIC OXIDATIONInventors: Robert Henry Campbell; Raleigh Warren Wise, both of Akron,Ohio US. Cl. ..260/247.1, 260/239 R, 260/239 BB, 260/293.4, 260l306.6 A,260/326.82,

Int. Cl. a ..'.C07d 87/46 Field of Search .260/247.l ,'306.6 A, 260/551S [561 References Cited UNITED STATES PATENTS 3,436,400 4/1969Freyermuth et al ..260/247.1

Primary Examiner-Alex Mazel Assistant Examiner-James H. TumipseedAttorney-Richard O. Zerbe, J. E. Maurer and Neal E. Willis [5 7]ABSTRACT Metal phthalocyanines are oxidation catalysts for thepreparation of sulfenamides in the reaction of primary or secondaryamines with 2-mercaptobenzothiaz0le,- an alkali metal salt of2-mercaptobenzothiazole, a dithiocarbamate, a dithiocarbamic acid, athiuram disulfide, or 2,2-dithiobis(benzothiazole).

17 Claims, N0 Drawings PREPARATION OF SULFENAMIDES BY CATALYTICOXIDATION REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part of application Ser. No. 634,096 filed Apr. 27, 1967now abandoned.

BACKGROUND OF THE INVENTION The invention pertains to the field ofchemical processes for preparing sulfenamides. The applicable U.S.patent classifications are found under Heterocyclic Carbon Compounds,more specifically Class 260247.l and 260306.6.

Certain sulfenamides are known to be useful vulcanization acceleratorsfor rubber, lubricating oil'additives and fungicides. It is known thatZ-mercaptobenzothiazole and 2,2'-dithiobis(benzothiazole) react withprimary and secondary amines to form sulfenamides in the presence ofcertain oxidizing agents. Oxidizing agents such as hypohalite, hydrogenperoxide, chlorine, potassium ferricyanide, and potassium .persulfateare taught in U.S. Pat. No. 2,762,814 (Cl. 260306.6) of Lunt assigned toMonsanto Chemicals Limited (1956). Sodium hypohalite is usedcommercially as an oxidizing agent in the preparation of sulfenamides. Alarge volume of sodium hypohalite is needed to prepare a sulfenamide.Usually, 25 to 50 percent excess sodium hypohalite is needed over thetheoretical amount. Our new catalytic oxidation method for preparingsulfenamides does not require the sodium hypohalite solution used in thepast; Instead, our process uses catalyst and oxygen or air as theoxidant. Consequently, the volume required in the past for the sodiumhypohalite solution is available for reactants inour'process.

Metal phthalocyanines and their sulfonates are known catalysts forpreparing organic disulfides. U.S. Pat. No. 3,116,329 (Cl. 260-567) ofHayes assigned to M can be cobalt, manganese, vanadium, chromium,nickel, iron, copper, or platinum. R can be hydrogen, barium, sodium,potassium, ammonium, calcium, zinc, or magnesium. The x, x, x" and x'independently are numbers from 0 to 4. The numerical values of y, y, y",and y' are dependent on the cation charge and on the values of x, x, x",and x "'in order to satisfy the-stoichiometry. In the non-sulfonatedcobalt phthalocyanines of this invention x, x, x", and x'. and y, y, y",and y are 0.

The function of the sulfonic acid group is to make the phthalocyaninewater soluble. Polar functional groups other than S(:0),Ol-l, forexample, OH, -COOH, or -P- (O)(OII)2 can be used to make thephthalocyanines water soluble.

The sulfenamides of this invention are formed by reactingZ-mercaptobenzothiazole, an alkali metal salt ofZ-mercaptobenzothiazole, preferably sodium Z-mercaptobenzothia'zole, adithiocarbamate, a dithiocarbamic acid, a thiuram disulfide, or2,2'-dithiobis(benzothiazole) with a primary or secondary amine. Thereaction is carried outin the presence of a metal phthalocyaninecatalyst and an oxygen-containing gas. The reaction is preferablycarried out in solvent or diluent and the reaction mixture should bealkaline. Examples of the thiuram disulfides useful in theprocess ofthis invention are found in U.S. Pat. No. 3,116,328, supra,

260-247) (1947) of Smith assigned to the Firestone Universal oilProducts Company (1963) teaches the use of Group VIII metalphthalocyanines in the prese'nce of an oxidizing agent to preparethiuramdisulfides from amines and carbon disulfide. U.S. Pat. No.3,116,328 (Cl. 260-567) to Cox assigned to Universal Oil ProductsCompany (1963) teaches the use of a Group VIII metal phthalocyaninecatalyst for the catalytic oxidation of an alkali salt of adialkyldithiocarbamic acid to prepare tetraalkylthiuram disulfides.British Pat. No. 963,122 assigned to American Cyanamid Company teachesthe use of a water-solublemetalphthalocyanine or an alkali neutralizedwater-soluble salt thereof as catalyst in the presence of oxygen toprepare aromatic disulfides from thiophenols.

SUMMARY A number of phthalocyanines and their derivatives are oxidationcatalysts for the preparation of sulfenamides. The formula for thepreferred catalysts useful in this invention is Tire and Rubber Companyand British Pat.. No. 880,912 assigned to Imperial Chemical Industries,Ltd. (1961 which disclose that the nitrogen substituents of thedithiocarbamic acid nucleus are alkyl or together constitutecycloalkylene or cyclodialkyleneoxy, for example, methyl, ethyl, propyl,butyl, amyl, hexyl, heptyl, octyl, decyl, lauryl, benzyl, cyclohexyl,methylcyclohexyl, cyclopentamethylene, tamethylene, cyclohexamethylene,cyclodiethyleneoxy, and methylcyclodiethyleneoxy. Dithiocarbamates sosubstituted. are useful in the practice of the present invention.

I Similarly the primary or secondary amine may con tain one or two alkylradicals, for example, methyl,

for preparing sulfenamides. sulfenamides are prepared commercially byusing sodium hypohalite as an oxidizing agent. We have found that theuse of sodium hypohalite, which must be used in excess and utilizes alarge methylcyclopen- PREFERRED EMBODIMENTSN,N-Diethyl-2-benzothiazolesulfenamide To prepareN,N-diethyl-2-benzothiazolesulfenamide, 75.1 grams of 96.8 percent2-mercaptobenzothiazole (0.436 mol.) is added to a 400 ml. beaker. Then225 ml. of distilled water and 40.1 grams of diethylamine (0.55 mol.)are added to the beaker. The mixture is stirred until solution isobtained. The apparent pH of this solution is 10.9. The solution istransferred to a 1- liter Parr autoclave using about 20 ml. of washwater. The barium salt. of cobalt phthalocyanine sulfonate (0.225 grams)is added to the autoclave solution as the oxidation catalyst. The amountof catalyst represents 0.3 percent (w/w) based on the weight of2-mercaptobenzothiazole.

The autoclave is assembled and purged with oxygen at ambient temperatureand pressure for about 2 minutes to remove most of the nitrogen. Theoxygen vent is closed and 70 p.s.i. of oxygen, is'applied to the system.The reactor is heated to 70 C. by a steam-water mixture flowing throughthe coils of the autoclave. The mixture is stirred continuously duringthe reaction period. Progress of the reaction is noted by a decrease inoxygen pressure within the reactor. When the pressure drops to 50 or 40p.s.i., additional oxygen is added to make 70 p.s.i. of oxygen pressure.This type of control is used throughout the reaction. After a 105-minuteperiod, the reactionmixture is cooled to room temperature and thereaction mixture is transferred to a separatory flask. The heavy oilysulfenamide layer is removed from the flask. The oily sulfenamide isdried at room temperature under vacuum overnight with a slight nitrogenpurge. Seventy-three grams of product or a 70.5 percent yieldof:N,N-diethyl-2-benzothiazolesulfenamide is obtained based on theamount of 2-mercaptobenzothiazole used.

The ultraviolet spectrum of the product in methanol is typical ofsulfenamides showing A (maximum) 278 mp with an a, of 49.5 l/gcm. withweaker absorption bands at 288 my. and 299 mu. Elemental analysis of theN,N-diethyl-2-benzothiazolesulfenamide shows 26.06 percent sulfur and 11.36 percent nitrogen. Calculated percentages for'N,N-diethyl-2-benzothiazolesulfenamide are 26.46 percent sulfur and 11.75 percent nitrogen. The infrared spectrum is consistent with theproposed structure.

N-tert-Butyl-Z-Benzothiazolesulfenamide To prepare N-tertbutyl-2-benzothiazolesulfenamide, an aqueous sodiumZ-mercaptobenzothiazole solution is made by dissolving 50.1 grams ofZ-mercaptobenzothiazole (0.3 mol.)-in 232 ml. of 1.3 N sodium hydroxidein a 400 ml. beaker. The apparent pH is adjusted to 8.0 using a 25percent sulfuric acid solution. To this mixture, 27.4 grams oftert-but'ylamine (0.375 mol.) are added and the apparent pH is adjustedfrom 10.6 to 10.4 with 25 percent sulfuric acid. The. mixture istransferred to a l-liter Parr autoclave and 0.15grams of barium salt ofcobalt'phthalocyanine sulfonate cata lyst is added. The reaction iscarried out in a similar manner to the diethylamine reaction, supra, atC. with a maximum oxygen pressure of 60 p.s.i. The oxygen line is shutoff and when the pressure drops from 60 p.s.i. to 55 or 50 p.s.i. thevalve is-reopened to bring the oxygen pressure in the autoclave back to60 p.s.i. The reaction is stopped after 2 hours and cooled to roomtemperature. The product is filtered and dried to give 53.8 grams ofsolids that assay 88.5 percent for N-tert-butyl-Z-benzothiazolesulfenamide and 11 percent cent yield forN-tert-butyl-2-benzothiazolesulfenamide based on the amount ofZ-mercaptobenzothiazole used.

To prepare N-tert-butyl-2-benzothiazolesulfenamide from2,2'-dithiobis(benzothiazole), 74.7 grams of2,2'-dithiobis(benzothiazole) and 225 ml. distilled water are added to a400 ml. beaker. To the mixture is added 41.1 grams of tert-butylamine(0.565 mol.) and 0.1125 gram of barium salt of cobalt phthalocyaninesulfonate (0.15 percent) based on 2,2-dithiobis(benzothiazole). Themixture is stirred and the resulting apparent pH is 11.9. The reactionmixture is transferred to a '1-liter Parr autoclave and treated withoxygen under 60 p.s.i. at 70 C. for 2 hours in a similar manner to thediethylamine reaction, supra. The mixture is stirred continuously duringthe reaction and as the oxygen pressure drops to 45 to 50 p.s.i.additional oxygen is added to make 60 p.s.i. oxygen pressure. After 2hours the reaction mixture is removed from the autoclave and has anapparent pH of 11.0. The mixture is filtered and the solids are dried.The dried solids weigh 78.5 grams and assay 83.9 percent forN-tert-butyl-2- benzothiazolesulfenamide. These results indicate anoverall yield of 55.5 percent sulfenamide based on the amount ofstarting 2,2-dithiobis(benzothiazole).

A recycled catalyst is useful; in our invention. To illustrate the useof a recycled catalyst, 83.5 grams of 2-mercaptobenzothiazole (0.5mol.), 109.6 grams of tert-butylamine (1.5 mol.), and 225 ml. ofdistilled water are added to a 600 ml. beaker. The mixture is stirredand the pH isadjusted to 10.8 using glacial acetic acid. The mixture istransferred to a 1-liter Parr autoclave and 0.25 grams of the bariumsalt of cobalt phthalocyanine sulfonic acid is'added'. The reaction iscarried out at 70 C. with a maximum of 60 p.s.i. of oxygen pressure for30 minutes. During this time, the reaction rapidly consumes oxygen sothat a total of 235 p.s.i. are added. The reaction is cooled andfiltered to give" 82.6 grams .of solidN-tertbutyl-2-benzothiazolesulfenamide upon drying. The filtrate isreturned tothe autoclave and 83.5 grams of Z-mercaptobenzothiazole and37 grams'of tert-butylamine are added. No additional catalyst is used.The reaction is continued for two hours to yield 1 19.2 grams of productwhich assays 91.5 percent for sulfenamide. The overall yield whichincluded both cycles based on MBT is 80.5 percent sulfenamide.

In using cobalt phthalocyanine as catalyst for the preparation of2-tert-butylaminothio(benzothiazole) anorganic solvent is advantageousbecause of insolubility of the catalyst in polar solvent systems. Toprepare the sulfenamide using cobalt phthalocyanine add 75.1 grams of 97percent MBT (0.437 mol.) and 275 ml. of pyridine to a 400ml. beaker.Stir the mixture until solution is obtained. Then add 0.225 grams ofcobalt phthalocyanine (0.3 percent by weight based on MBT) and 41.1grams of tert-butylamine (0.562 mol.)

to the beaker. The apparent pH using a glass calomel electrode is now10.3. The reaction mixture is transferred to a l-liter Parr autoclave.The reaction is carried out in the temperature range of 68 to 75 C.under 45 to 60 p.s.i. of oxygen pressure for a period of 1.5 hours.After the reaction is terminated, the apparent pH is still 10.3. Thereaction mixture is treated with 1,100 ml. of water and filtered. Theresidue is washed with an additional 200 ml. of water and dried to give77 grams of product that assays 98.9 percent fortertbutylaminothio(benzothiazole). This gives a 73.4 percent overallyield of sulfenamide based on the amount of starting MBT.

2(2,6-Dimethyl-4-Morpholinothio)Benzothiazole To prepare2-(2,6-dimethyl-4-morpholinothio)benzothiazole 75.1 grams of 96.8percent 2-mercaptobenzothiazole (0.436 mol.) and 200 ml. of anisopropanolwater solution are added to a 400 ml. beaker. Theisopropanol-water solution is composed of l-volume of water to l-volumeof isopropanol. Eighty-three grams of 2,6 -dimethyl-morpholine (0.72mol.) and 20 ml. of 5 N aqueous NaOH are added to the mixture in thebeaker. The resulting apparent pH is 9.38. The mixture is transferred toa l-liter Parr autoclave using 25 ml. of 1:1 isopropanol-water washsolution. Then the barium salt of cobalt phthalocyanine sulfonic acidcatalyst (0.225 grams) is added. The reaction is carried out at 70 C.with oxygen pressure varying from p.s.i. to 70 p.s.i. in a similarmanner to the diethylamine reaction, supra. The reaction is stoppedafter 195 minutes. The reaction mixture is filtered and the residue isair dried to give 89 grams of product. This product assays 94.5 percentfor 2-(2,6-dimethyl-4-morpholinothio)benzothiazole to give a 69 percentoverall yield based on 2-mercaptobenzothiazole.

2-(Morpholinothio)Benzothiazole To prepare2-(morpholinothio)benzothiazole 75.1 grams of 96.8 percentZ-mercaptobenzothiazole (0.436 mol.) and 200 ml. of distilled water areadded to a 400 ml. beaker. To this mixture are added 78.4 grams ofmorpholine (0.90 mol.) and 0.225 grams of barium salt of cobaltphthalocyanine sulfonic acid. The mixture'is stirred and transferred toa 1liter Parr autoclave with the aid of 25 ml. of water. A 100 ml.aliquot of chloroform is added to the autoclave. Then the reaction iscarried out in a similar manner to the diethylamine reaction, supra, at:t70 C. with 35 to 70 p.s.i. oxygen pressure for three hours. After thereaction is stopped, the mixture is cooled to room temperature. Athreephase mixture is obtained: an aqueous layer above, and a heavychloroform layer which contains solids. The chloroform layer isseparated from the aqueous layer and then filtered to remove the solidmaterial which is 2,2'-dithiobis(benzothiazole). The chloroform solutionis stripped under vacuum with a nitrogen purge at room temperature togive 41 grams of crude 2- (morpholinothio)-benzothiazole. The productassays 97.6 percent sulfenamide to give an overall yield of 31 percent2-(morpholinothio)benzothiazole based on the starting amount ofZ-mercaptobenzothiazole.

N-Cyclohexyl-2-Benzothiazolesulfenamide TheN-cyclohexyl-2-benzothiazolesulfenamide is prepared in a similar mannerto the diethylamine reaction, supra, except cyclohexylamine is used inplace of diethylamine. A yield of 70.3 percent N-cyclohexyl-2-benzothiazolesulfenamide is obtained.

2-(l-lexahydroazepinl -ylthio)benz'othiazole The2--(hexahydroazepin-l-ylthio)benzothiazole is prepared in a similarmanner to the diethylamine reaction, supra, except hexamethyleneimine isused as a reactant in place of diethylamine. The 2-(hexahydroazepin-l-ylthio)benzothiazole is obtained in a 25.7 percentyield.

N,N-Diethylthiocarbamyl-N'-Cyclohexylsulfenamide To prepareN,N-diethylthiocarbamyl-N'-cyclohexylsulfenamide, 21.9 grams ofdiethylamine (0.3 mol.), 12.0 grams sodium hydroxide and 400 ml. ofwater are added to a 1-liter, three-necked reaction flask. The solutionis stirred and cooled while 22.8 grams of carbon disulfide (0.3 mol.) isslowly added to form the sodium salt of N,N-diethyldithiocarbamic acid.The reaction mixture is stirred at 20 C. for 20 minutes to insurecomplete formation of the salt, after which 60.0 grams ofcyclohexylamine (0.6 mol.) and 0.154 gram of the barium salt of cobaltphthalocyanine sulfonic acid are added. The apparent pH of this solutionis l 1.7. Suffrcient 6N hydrochloric acid ml.) is added with stirringand cooling at 60 C. to give an apparent pH of 1 1.0.

The reaction solution is stirred and the temperature maintained in therange of 3542 C., while oxygen is sparged through the solution atatmospheric pressure for 3 hours and 20 minutes. After this time thereaction is allowed to stand overnight and an oil separates out whichsolidifies on stirring. The solid is filtered off and dried to give 28grams of crude greenish colored product (38 percent yield) melting at5661 C. Some of the material purified by silica chromatography usingbenzene as eluant gives crystals melting at 64 65.2 C. The reportedmelting point is 64-65 C., J. Org. Chem., XIV, 925 (1949). The infraredspectrum is consistent with the proposed structure by showing an N-Hstretch (3,220 cmf), C-l-l stretch (2,940 cm), and no carbonyl ispresent in the 1,600-1 ,850 cm." region. Strong bands at 1,492, 1,265,and 1,200 cm? are present in the thioureide region of the infraredspectrum. The elemental analyses are consistent with the proposedstructure: Sulfur found 26.88 percent and 26.84 percent (Theory 26.03percent); Nitrogen found 11.33 percent (Theory 11.36 percent).Comparable results are obtained in preparing other sulfenamides fromdithiocarbamic acids.

The preferred catalyst of our invention is the barium salt of cobaltphthalocyanine sulfonic acid. The barium salt of cobalt phthalocyaninesulfonic acid can be prepared in the following manner. The cobaltphthalocyanine is sulfonated, Approximately 60 ml. of 20-23 percentfuming sulfuric acid is charged into a three-necked reaction flask.Exactly 15 grams of cobalt phthalocyanine is added in small amounts withstirring. The temperature is held below 40 C. during the addition. Aftercomplete addition of the cobalt phthalocyanine, the temperature israised to C. and maintained at this temperature for 3 hours. Thereaction mixture is cooled to 20 C. and 300 ml. of water are addedslowly. The diluted solution is transferred to a beaker and the pHadjusted to pH 5.0 with barium carbonate. The mixture is filtered toremove barium sulfate and the filtrate is stripped to dryness. A l2-gramyield of the barium salt of cobalt phthalocyanine sulfonic acid isobtained.

The crystals are reddish-purple and completely watersoluble. The productassays: Nitrogen, 8.13 percent; Sulfur, 7.02 percent and 6.65 percentwhich gives an average of 3.4 sulfonate groups per molecule.

Pure oxygen is' the preferred oxidizing agent for out process. However,mixtures containing oxygen, for example, air can be used. The pressurewithin the autoclave can vary from atmospheric to 500 p.s.i. Thepreferred pressure range is between about to 75 p.s.i. An alkalinemedium is required for our process. A pH range between 7.5 to 13apparent pH units may be used in our process. Under alkaline conditions,the thiazole reactant of the reaction mixture can vary from essentiallyall Zmercaptobenzothiazole to essentially all sodium2-mercaptobenzothiazole. In a reaction mixture usingZ-mercaptobenzothiazole as a starting material, the apparent pH must bealkaline. The preferred pH range is from about 9.0 to about 1 1.9. Thetemperature range preferred is about 45 to about 80 C. However, thetemperature can be lowered or raised if other factors such as rate ofreaction, hydrolysis, and overoxidation are compromised. The reactiontime depends upon the reaction conditions. Higher temperature, high pH,increased amine concentrations, increased catalysts concentrations, andhigher pressures tend to de crease the required reaction time. Preferredcatalysts concentrations are 0.1 percent to 0.3 percent by weight basedon thiazole reactant. Lower concentrations can be used if longerreaction times and other conditions such as increases in oxygenpressure, amine concentrations, and temperature are employed. Thereaction occurs in aqueous, mixed and miscible organic-aqueous, mixedand immiscible organic-aqueous, or organic solvent systems.

Copper Phthalocyanine To prepare 2-tert-butylaminothio(benzothiazole)using fi-copper phthalocyanine there is added 83.5 grams ofZ-mercaptobenzothiazole (0.5 mol.) to a oneliter Parr autoclave togetherwith 250 ml. of pyridine, 73 .l grams of tert-butylamine (1.0 mol.), and1.25 grams of B-copper phthalocyanine. The reaction is carried out under50 to 70 pounds per square inch of oxygen for 7 hours at a temperaturewithin the range of 70 to 80 C. As the oxygen pressure drops from 70p.s.i. to 50 p.s.i., additional oxygen is admitted to increase thepressure back to 70 p.s.i.

The reaction solution is filtered to remove a small amount of bluesolids then 2,000 ml. of water added and stirred. The productprecipitates out, and it is filtered off. After air drying, the productis weighed to give 66 grams ofN-tert-butyl-2-(benzothiazolesulfenamide), representing a yield of 55percent. The material assays 99 percent by UV analysis. No significantamounts of 2,2'-dithiobis(benzothiazothiazole) is detected when theproduct is tested for methanol insolubles.

Vanadium Phthalocyanine The catalyst vanadium phthalocyanine is used toprepare 2-tert-butylaminothio(benzothiazole) in the manner described forusing copper phthalocyanine. Only 1.0 gram of vanadium phthalocyanine(prepared according to J.C.S., 1936, 1736) is used to obtain a yield of35.2 grams (29.6 percent) of N-tert-butyl-Z-(benzothiazolesulfenamide).

Platinum Phthalocyanine The catalyst platinum phthalocyanine is used forpreparing I 2 tert-butylaminothio(benzothiazole) in the 1. The processfor preparing a sulfenamide by reacting primary or secondary amine ofthe formula respectively RNH and where R and R independently areselected from the group consisting of alkyl of l to 12 carbon atoms,benzyl, cyclopentyl, cyclohexyl and methylcyclohexyl or taken with theNH, R and R together form a heterocycle selected from the groupconsisting of pyrrolidine, piperidine, methylpiperidine, 2-methyl-5-ethylpiperidine, 2-ethylpiperidine, morpholine,methylmorpholine,dimethylmorpholine and hexamethylenimine and a compound selected fromthe group consist- ,ing of alkali metal salt of2-mercaptoben'zothiazole,

2-mercaptobenzothiazole, 2,2 -dithiobis(benzothiazole), N-substituteddithiocarbamic acid, alkali metal-salt of N-substituted dithiocarbamicacid, N- substituted thiuram disulfide, the nitrogen substltuents ofsaid dithiocarbamic acid, alkali metalsalt thereof and thiuram disulfidebeing selected from the group consisting of alkyl of l to 12 carbonatoms, benzyl, phenyl, tolyl, cyclopentyl, cyclohexyl andmethylcyclohexyl or together with the nitrogen constitute a heterocyclicradical selected from the group consisting of piperidino,methylpiperidino, hexamethyleniminyl, morpholino, methylmorpholino,dimethylmorpholino, 2-methyl-5-ethylpiperidino, 2-ethylpiperidino andpyrrolidinyl, forming the sulfenamide in the presence of oxygen or airand an effective amount of metal phthalocyanine catalyst wherein themetal is selected from a group consisting of cobalt, manganese, vanadiumchromium, nickel, iron, platinum, and copper or water soluble derivativeof metal phthalocyanine catalyst characterized by the presence of apolar functional substituent selected from the group consisting of S(O)-0H, OH, COOH and PO(OH),.

2. The process for preparing a sulfenamide by react-- ing primary orsecondary'amine of the formula respectively RNH and where R and Rindependently are selected from the group consisting of alkyl of l to 12carbon atoms, benzyl, cyclopentyl, cyclohexyl and methylcyclohexyl ortaken with the NH, R and R together form a heterocyacid.

substituted thiuram disulfide, the nitrogen substitutents of said alkalimetal salt of dithiocarbamic acid and thiuram sulfide being selectedfrom the group consisting of alkyl of one to 12 carbon atoms, benzyl,phenyl, tolyl, cyclopentyl, cyclohexyl and methylcyclohexyl or togetherwith the nitrogen constitute a heterocyclic radical selected from thegroup consisting of piperidino,

methylpiperidino, hexamethyleniminyl, morpholine,

methylmorpholino, dimethylmorpholino, 2-methyl-5- ethylpiperidino,2-ethylpiperidino and pyrrolidinyl, the reaction being conducted inreaction medium selected from the group consisting of aqueous, mixed andmiscible organic-aqueous, organic and mixed and immiscibleorganic-aqueous, forming the sulfenamide in the presence of oxygen orair under a pressure of about to 500 psi and an effective amount ofcobalt phthalocyanine or cobalt phthalocyanine sulfonate catalyst at atemperature between the range of about 25 C. to about 100 C. and a pHbetween the range of about 7.5 to about 13.0.

3. A process according to claim 2 wherein the amine is tert-butylamine,hexamethyleneimine, morpholine, 2,6-dimethylmorpholine, cyclohexylamine,or diethylamine.

4. A process according to claim 3 which comprises reactingtert-butylamine with 2-mercaptobenzothiazole and formingN-tert-butyl-2-benzothiazolesulfenamide.

5. A process according to claim 4 wherein the catalyst is the bariumsalt of cobalt phthalocyanine sulfonic acid.

6. A process according to claim 3 which comprises reacting diethylaminewith Z-mercaptobenzothiazole and formingN,N-diethyl-2-benzothiazolesulfenamide.

7. The process according to claim 6 wherein the catalyst is the bariumsalt of cobalt phthalocyanine sulfonic 8. A process according to claim 3which comprises reacting cyclohexylamine with Z-mercaptobenzothiazoleand forming N-cyclohexyl-2-benzothiazolesulfenamide.

9. A process according to claim 8 wherein the catalyst is the bariumslat of cobalt phthalocyanine sulfonic acid.

10. A process according to claim 3 which comprises reacting2,6-dimethylmorpholine with 2-mercaptoben-' zothiazole and formingmorpholinothio)benzothiazole.

11. A process according to claim 10 wherein the catalyst is the bariumsalt of cobalt phthalocyanine sulfonic acid.

12. A process according to claim 3 which comprises reacting morpholinewith Z-mercaptobenzothiazole and forming2-(morpholinothio)benzothiazole.

13. A process according to claim 12 wherein the catalyst is the bariumsalt of cobalt phthalocyanine sulfonic acid.

.14. A process according to claim 3 which comprises reactinghexamethyleneimine with Z-mercaptobenzothiazole and forming2-hexahydroazepin-l-ylthio)benzothiazole.

15. A process according to claim 14 wherein the catalyst is the bariumsalt of cobalt phthalocyanine sulfonic acid.

16. A process according to claim 3 which comprises reactingcyclohexylamine with N,N-diethyldithiocar- 2-( 2,6-dimethyl-4- bamicacid and forming N,N-diethylthiocarbamyl-N'- fonic acid.

2. The process for preparing a sulfenamide by reacting primary orsecondary amine of the formula respectively RNH2 and where R and R''independently are selected from the group consisting of alkyl of 1 to 12carbon atoms, benzyl, cyclopentyl, cyclohexyl and methylcyclohexyl ortaken with the NH, R and R'' together form a heterocycle selected fromthe group consisting of pyrrolidine, piperidine, methylpiperidine,2-methyl-5-ethylpiperidine, 2-ethylpiperidine, morpholine,methylmorpholine, dimethylmorpholine, and hexamethylenimine and acompound selected from the group consisting of sodium salt of2-mercaptobenzothiazole, 2-mercaptobenzothiazole,2,2''-dithiobis(benzothiazole), alkali metal salt of N-substituteddithiocarbamic acid, N-substituted thiuram disulfide, the nitrogensubstitutents of said alkali metal salt of dithiocarbamic acid andthiuram sulfide being selected from the group consisting of alkyl of oneto 12 carbon atoms, benzyl, phenyl, tolyl, cyclopentyl, cyclohexyl andmethylcyclohexyl or together with the nitrogen constitute a heterocyclicradical selected from the group consisting of piperidino,methylpiperidino, hexamethyleniminyl, morpholino, methylmorpholino,dimethylmorpholino, 2-methyl-5-ethylpiperidino, 2-ethylpiperidino andpyrrolidinyl, the reaction being conducted in reaction medium selectedfrom the group consisting of aqueous, mixed and miscibleorganic-aqueous, organic and mixed and immiscible organic-aqueous,forming the sulfenamide in the presence of oxygen or air under apressure of about 10 to 500 psi and an effective amount of cobaltphthalocyanine or cobalt phthalocyanine sulfonate catalyst at atemperature between the range of about 25* C. to about 100* C. and a pHbetween the range of about 7.5 to about 13.0.
 3. A process according toclaim 2 wherein the amine is tert-butylamine, hexamethyleneimine,morpholine, 2,6-dimethylmorpholine, cyclohexylamine, or diethylamine. 4.A process according to claim 3 which comprises reacting tert-butylaminewith 2-mercaptobenzothiazole and formingN-tert-butyl-2-benzothiazolesulfenamide.
 5. A process according to claim4 wherein the catalyst is the barium salt of cobalt phthalocyaninesulfonic acid.
 6. A process according to claim 3 which comprisesreacting diethylamine with 2-mercaptobenzothiazole and formingN,N-diethyl-2-benzothiazolesulfenamide.
 7. The process according toclaim 6 wherein the catalyst is the barium salt of cobalt phthalocyaninesulfonic acid.
 8. A process according to claim 3 which comprisesreacting cyclohexylamine with 2-mercaptobenzothiazole and formingN-cyclohexyl-2-benzothiaZolesulfenamide.
 9. A process according to claim8 wherein the catalyst is the barium slat of cobalt phthalocyaninesulfonic acid.
 10. A process according to claim 3 which comprisesreacting 2,6-dimethylmorpholine with 2-mercaptobenzothiazole and forming2-(2, 6-dimethyl-4-morpholinothio)benzothiazole.
 11. A process accordingto claim 10 wherein the catalyst is the barium salt of cobaltphthalocyanine sulfonic acid.
 12. A process according to claim 3 whichcomprises reacting morpholine with 2-mercaptobenzothiazole and forming2-(morpholinothio)benzothiazole.
 13. A process according to claim 12wherein the catalyst is the barium salt of cobalt phthalocyaninesulfonic acid.
 14. A process according to claim 3 which comprisesreacting hexamethyleneimine with 2-mercaptobenzothiazole and forming2-hexahydroazepin-1-ylthio)benzothiazole.
 15. A process according toclaim 14 wherein the catalyst is the barium salt of cobaltphthalocyanine sulfonic acid.
 16. A process according to claim 3 whichcomprises reacting cyclohexylamine with N,N-diethyldithiocarbamic acidand forming N,N-diethylthiocarbamyl-N''-cyclohexylsulfenamide.
 17. Aprocess according to claim 16 wherein the catalyst is the barium salt ofcobalt phthalocyanine sulfonic acid.